Sill Pans and Flashing 
Window Fitters Guide to Window Installation 
20                ©2022 AWDI, LLC Do not reproduce without permission
Step 3:
Using adhesive-backed
flashing material (Vycor
or equal) place flashing
around each jamb,
overlapping the sill
flashing.
Place adhesive-backed
flashing across the
header extending up
and over the jamb
flashing.
Step 1:
Using Adhesive-backed
Flashing Material place
flashing over rough sill
extending 5 inches
down the front, and 4
inches up each side.
Be careful not to tear or
buckle the membrane. 
NOTE: If you’re not
using a pre-formed sill
pan, you can create the
effect by installing a 
1 x 2 to create a 
backdam before 
applying the flashing
Step 1
Step 2
Step 3
Step 2:
Assemble Sill Pan
(Jam-Sill or equal) to fit
between the jambs and
set on top of the sill.
Do not anchor the 
sill pan to the rough 
sill with fasteners as
doing so will create 
a leak path.
Fix the sill pan to 
each jamb using the
head of a roofing nail,
as shown below.
Alternate 1:
If house wrap has been
applied to the wall 
prior to beginning 
the window or door
installation (Method B),
cut the house wrap in
such a way to be able
to fold it back, and tape
it out of the way.
Flashing materials
must adhere directly 
to the sheathing for 
maximum bond.
If adhered to house-
wrap, flashing may
direct water under the
wrap and into the 
cavity between the 
window or door and 
the rough opening.
Alternate 2 and 3:
If the house wrap has been moved aside, it can
now be un-taped and placed over the second
layer of self-adhesive flashing to complete the
installation.  Again, take care to leave the bottom
free for drainage into the drainage plane.
(See full detailed steps in the New Construction
Installation section elsewhere in this manual).
Alternate 2
Alternate 3
Alternate 1
SAMPLE MANUAL

View this content as a flipbook by clicking here.